[Guidelines for application of computer-assisted indocyanine green molecular fluorescence imaging in diagnosis and surgical navigation of liver tumors (2019)]

Fluorescence-guided Surgery for Hepatocellular Carcinoma: From Clinical Practice to Laboratories

Fluorescence navigation is a novel technique for accurately identifying hepatocellular carcinoma (HCC) lesions during hepatectomy, enabling real-time visualization. Indocyanine green-based fluorescence guidance has been commonly used to demarcate HCC lesion boundaries, but it cannot distinguish between benign and malignant liver tumors. This review focused on the clinical applications and limitations of indocyanine green, as well as recent advances in novel fluorescent probes for fluorescence-guided surgery of HCC. It covers traditional fluorescent imaging probes such as enzymes, reactive oxygen species, reactive sulfur species, and pH-sensitive probes, followed by an introduction to aggregation-induced emission probes. Aggregation-induced emission probes exhibit strong fluorescence, low background signals, excellent biocompatibility, and high photostability in the aggregate state, but show no fluorescence in dilute solutions. Design strategies for these probes may offer insights for developing novel fluorescent probes for the real-time identification and navigation of HCC during surgery.

Laboratory scoring system to predict hepatic indocyanine green clearance ability during fluorescence imaging-guided laparoscopic hepatectomy

BACKGROUND

Indocyanine green (ICG) fluorescence played an important role in tumor localization and margin delineation in hepatobiliary surgery. However, the preoperative regimen of ICG administration was still controversial. Factors associated with tumor fluorescence staining effect were unclear.

AIM

To investigate the preoperative laboratory indexes corelated with ICG fluorescence staining effect and establish a novel laboratory scoring system to screen specifical patients who need ICG dose adjustment.

METHODS

To investigate the predictive indicators of ICG fluorescence characteristics in patients undergoing laparoscopic hepatectomy from January 2018 to January 2021 were included. Blood laboratory tests were completed within 1 wk before surgery. All patients received 5 mg ICG injection 24 h before surgery for preliminary tumor imaging. ImageJ software was used to measure the fluorescence intensity values of regions of interest. Correlation analysis was used to identify risk factors. A laboratory risk model was established to identify individuals at high risk for high liver background fluorescence.

RESULTS

There were 110 patients who were enrolled in this study from January 2019 to January 2021. The mean values of fluorescence intensity of liver background (FI-LB), fluorescence intensity of gallbladder, and fluorescence intensity of target area were 18.87 ± 17.06, 54.84 ± 33.29, and 68.56 ± 36.11, respectively. The receiver operating characteristic (ROC) curve showed that FI-LB was a good indicator for liver clearance ability [area under the ROC curve (AUC) = 0.984]. Correlation analysis found pre-operative aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase, adenosine deaminase, and lactate dehydrogenase were positively associated with FI-LB and red blood cell, cholinesterase, and were negatively associated with FI-LB. Total laboratory risk score (TLRS) was calculated according to ROC curve (AUC = 0.848, sensitivity = 0.773, specificity = 0.885). When TLRS was greater than 6.5, the liver clearance ability of ICG was considered as poor.

CONCLUSION

Preoperative laboratory blood indicators can predict hepatic ICG clearance ability. Surgeons can adjust the dose and timing of ICG preoperatively to achieve better liver fluorescent staining.

Applications of Magnetic Particle Imaging in Biomedicine: Advancements and Prospects

Magnetic particle imaging (MPI) is a novel emerging noninvasive and radiation-free imaging modality that can quantify superparamagnetic iron oxide nanoparticles tracers. The zero endogenous tissue background signal and short image scanning times ensure high spatial and temporal resolution of MPI. In the context of precision medicine, the advantages of MPI provide a new strategy for the integration of the diagnosis and treatment of diseases. In this review, after a brief explanation of the simplified theory and imaging system, we focus on recent advances in the biomedical application of MPI, including vascular structure and perfusion imaging, cancer imaging, the MPI guidance of magnetic fluid hyperthermia, the visual monitoring of cell and drug treatments, and intraoperative navigation. We finally optimize MPI in terms of the system and tracers, and present future potential biomedical applications of MPI.

Application of Near-Infrared Fluorescence Imaging Technology in Liver Cancer Surgery

Background. Hepatocellular carcinoma, among the most common malignant digestive system tumorsworldwide, is most effectively treated with precise surgical resection. Near-infrared fluorescence imaging technology is being increasingly used clinically and has achieved great initial results in the navigation of liver cancer surgery. Methods. This review describes the application of indocyanine green fluorescence (ICG) imaging technology with near-infrared window I in the navigation of liver cancer surgery, explores novel fluorescent probes and near-infrared window II fluorescence imaging technology, and discusses the development status of the 2 emerging tools. Results. ICG fluorescence imaging technology can precisely localize the tumor, reveal the boundary of liver cancer or liver segment, and identify the bile leakage. The novel fluorescent probe is more targeted than ICG, which makes the detection of cancer more accurate. Near-infrared window II fluorescence imaging technology can lead to outstanding gains in deeper detection, higher resolution, and fidelity. But, due to the shortcomings of machine and probe, it is not widely used in clinical. Conclusion. Near-infrared fluorescence imaging has great development potential. With the advent of precision medicine and the progress of various biotechnology studies, fluorescence imaging technology will be better developed and applied in the diagnosis, surgical navigation, and treatment of liver cancer.

Consensus recommendations of three-dimensional visualization for diagnosis and management of liver diseases

Three-dimensional (3D) visualization involves feature extraction and 3D reconstruction of CT images using a computer processing technology. It is a tool for displaying, describing, and interpreting 3D anatomy and morphological features of organs, thus providing intuitive, stereoscopic, and accurate methods for clinical decision-making. It has played an increasingly significant role in the diagnosis and management of liver diseases. Over the last decade, it has been proven safe and effective to use 3D simulation software for pre-hepatectomy assessment, virtual hepatectomy, and measurement of liver volumes in blood flow areas of the portal vein; meanwhile, the use of 3D models in combination with hydrodynamic analysis has become a novel non-invasive method for diagnosis and detection of portal hypertension. We herein describe the progress of research on 3D visualization, its workflow, current situation, challenges, opportunities, and its capacity to improve clinical decision-making, emphasizing its utility for patients with liver diseases. Current advances in modern imaging technologies have promised a further increase in diagnostic efficacy of liver diseases. For example, complex internal anatomy of the liver and detailed morphological features of liver lesions can be reflected from CT-based 3D models. A meta-analysis reported that the application of 3D visualization technology in the diagnosis and management of primary hepatocellular carcinoma has significant or extremely significant differences over the control group in terms of intraoperative blood loss, postoperative complications, recovery of postoperative liver function, operation time, hospitalization time, and tumor recurrence on short-term follow-up. However, the acquisition of high-quality CT images and the use of these images for 3D visualization processing lack a unified standard, quality control system, and homogeneity, which might hinder the evaluation of application efficacy in different clinical centers, causing enormous inconvenience to clinical practice and scientific research. Therefore, rigorous operating guidelines and quality control systems need to be established for 3D visualization of liver to develop it to become a mature technology. Herein, we provide recommendations for the research on diagnosis and management of 3D visualization in liver diseases to meet this urgent need in this research field.